Pearl-otster.- 



-MOLLUSCA.- 



-PeCTENIDjE. 



375 



at a Slipper with Antony, took from her ear one of 

 two pearls valued at £80,729 3s. 4d., dissolved it in 

 vinegar, and drank it off. The traveller Tavernier, in 

 more modern times, informs us that he saw in Persia a 

 pearl, which had been brought from the fishery at 

 Catifa in Arabia, and then in the possession of the 

 Sliah of Persia, which was nearly one and a half inches 

 long, j^ths of an inch in diameter, and was valued at 

 £1 10,000. The two great iisheries of pearls are those at 

 Bahrein Island, in the Persian Gulf, and in the bay of 

 Condatchy in the Gulf of Manaar, off the island of 

 Ceylon. The fishery of this latter place varies very 

 much in value. In 1798 the revenue derived from it 

 to Government reached the large sum of £192,000, but 

 in 1828 it only brought £30,612. The Bahrein fishery, 

 which includes the whole trade of the Persian Gulf, 

 is estimated as worth from £300,000 to £310,000! 

 The worst and most valueless kinds of pearls taken at 

 Ceylon are " carried to China, to be burned into lime, 

 which the rich Chinese use, instead of lime, with the 

 betel leaf and areca nut." — (Bertolacci.) The small 

 pearls called seed pearls, from the Persian Gulf fishery, 

 find their way in large quantities into various parts 

 of India, where they are used in the composition of 

 the majoons or electuaries, so much valued by the 

 natives for their supposed stimulating and restorative 

 qualities. 



THE PEARL-OYSTER [Margaritiphora fimbriata), 

 represented in Plate 11, fig. 21, Margarita margariti- 

 fera, when adult, is of a solid thick substance, and of 

 a highly polished nature internally. This forms the 

 article called in commerce " mother of pearl," a sub- 

 stance now used in so many ways in ornamental work 

 — as inlaying cabinet work, forming knife handles, 

 paper cutters, buttons, and constructing toys and 

 fancy articles. Immense quantities of these shells are 

 annually imported into Great Britain. " There are 

 three principal kinds, which are worth from £2 to £4 

 per cwt. — 1st, The Silver-lipped, from the Society 

 Islands, of which about twenty tons are annually im- 

 ported to Liverpool; 2nd, The Black -lipped, from 

 Manilla, of which thirty tons were imported in 1851 ; 

 3rd, A smaller sort from Panama, two hundred tons 

 of which are aimually imported — in 1851 a single 

 vessel brought three hundred and forty tons." — 

 ( Woodward.) The animals of these shells are some- 

 times used as food. Morier says that those in the 

 Persian Gulf are considered excellent, and that there 

 is no difference to be perceived in respect of taste 

 between them and the common oyster. Most authors, 

 however, describe them as unfit for the table. Dam- 

 pier, in one of his voyages, found them in abun- 

 dance at Gorgonia, coast of Peru. " The fish," he says, 

 " is not sweet nor very wholesome ; it is as sHmy as a 

 shell-snail ; they taste very copperish if eaten raw, and 

 are best boyl'd. The Indians, who gather them for 

 the Spaniards, hang the meat of them on strings like 

 Jews-ears, and dry them before they eat them." In 

 another part of the coast of South America, he says 

 that they were " so large, that one stewed is a meal 

 for five men." " The crew," he adds, "ate them for 

 want of better food." When stewed with pepper and 

 vinegar, they were " very tolerable food." 



Family— SPONDYLIDiE. 



The Thorny oysters have the margins of the mantle 

 thickened and furnished with bright eye-spots or ocelli. 

 The shell is irregular, attached by the right valve, 

 radiately ribbed, spiny or foliaceous. The hinge has 

 two large interlocking teeth in each valve. 



Genus Spondylus, or Thorny Oyster. — This 

 genus (the only one) has in general a strong thick shell, 

 variously ornamented with spines or plates. The 

 beaks are apart from each other, and eared. The lower 

 valve has a peculiar triangular hinge area, divided by 

 a groove and enlarging as it gi'ows older; and the car- 

 tilage is placed in a pit which communicates at its base 

 with the external groove. These shells adhere to 

 foreign bodies, such as stones, coral, &c., by the right 

 valve, being cemented to these bodies without the 

 medium of an)' connecting membrane or ligament, and 

 becoming modelled to the foreign substance on which it 

 lies. In the inner laj'er of shell there are left in some 

 of the species, as in Spondylus rariaiis — hence called 

 the " Water-clam" — spaces or cavities which are filled 

 with water. Similar cavities are found in the Etheria:; 

 but these are generally like blisters or air bub- 

 bles, whilst in Spondylus the quantity of water con- 

 tained is often considerable and remains for a length of 

 time, perhaps years, after the shell is dry. These 

 cavities are produced by the border of the mantle 

 depositing shell more rapidly than the umbonal portion. 

 There are a good many species, and some of them are 

 beautiful shells and adorned with bright and lively 

 colours. The genus is represented in Plate 11, fig 22, 

 by Spondylus regius. 



Family— PECTENID^ (Tlie Scallops). 



The Scallops have a long foot, which secretes a 

 byssus. The margins of the mantle are double, the 

 inner hanging down somewhat like a curtain and finely 

 fringed ; and having at its base a row of conspicuous 

 round black spots, like eyes, called ocrlli, surrounded 

 by tentacular filaments. The shell of the Scallops is 

 free, not cemented, and is closed. The beaks are 

 placed near each other, and the dorsal edges are pro- 

 duced into ears. The ligament is internal, in a central 

 pit. The species are numerous ; they generally attach 

 themselves by a byssus to rocks and other marine 

 bodies, and sometimes cover extensive banks with their 

 shells. Their long and angulated foot is not at all 

 adapted for crawling, but it is used " chiefly as an 

 exploring organ and to anchor them when required." 

 '—(^Adams.) The animals are said to possess the power 

 of vision ; and the bright spots on the edge of the 

 mouth are believed by many conchologists to be the 

 eyes. Poll so considers them, and he named the animal, 

 "after Juno's watchman, the Argus, to whose mantle 

 you may suppose the hundred eyes of the fabled son of 

 Ariston had been transferred."— (JoAjis/oh.) When 

 young the Scallops are free and extremely active. 

 The fry of the common '• Quin," as it is called, Pcctcn 

 opercularis, has been particularly noticed by Dr. Lands- 

 borough. At the time he observed tliem they were 

 about the size of a fouqienny piece, and were seen in 



